Inductively powered lamp assembly

ABSTRACT

A lamp assembly configured to inductively receive power from a primary coil. The lamp assembly includes a lamp circuit including a secondary and a lamp connected in series. In a first aspect, the lamp circuit includes a capacitor connected in series with the lamp and the secondary to tune the circuit to resonance. The capacitor is preferably selected to have a reactance that is substantially equal to or slightly less than the reactance of the secondary and the impedance of the lamp. In a second aspect, the lamp assembly includes a sealed transparent sleeve that entirely encloses the lamp circuit so that the transparent sleeve is fully closed and unpenetrated. The transparent sleeve is preferably the lamp sleeve itself, with the secondary, capacitor and any desired starter mechanism disposed within its interior.

[0001] The present invention is a continuation-in-part of U.S.application Ser. No. 90/592,194 entitled “Fluid Treatment System,” whichwas filed on Jun. 12, 2000.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to lighting and more particularlyto a lamp assembly for use in connection with inductively poweredlighting.

[0003] Although not widely available, inductively coupled lightingsystems are known. A conventional inductively coupled lighting systemgenerally includes a primary circuit having a primary coil (or“primary”) that is driven by a power supply and a secondary circuithaving a secondary coil (or “secondary”) that inductively receives powerfrom the primary. Inductive couplings provide a number of advantagesover conventional direct electrical connections. First, inductivelycoupled lamps are typically safer and easier to connect and disconnectthan hardwired lamps. With direct electrical connections, it isgenerally necessary to manipulate electrical connectors when installingand removing the lamp assembly. This typically requires some effort andcreates a risk of electrical shock. Often, the electrical connectors areat least partially exposed, thereby increasing the risk of electricalshock. Inductively coupled lamps, on the other hand, do not require themanipulation of any electrical connectors. Instead, the secondary of thelamp assembly simply needs to be placed adjacent to the primary topermit the supply of power to the lamp assembly. Second, the eliminationof electrical connectors also increases the reliability of the system byeliminating the problems associated with conventional electricalconnectors. For example, conventional electrical connectors are subjectto corrosion and to wear. These problems are particularly acute in anoutdoor setting where environmental conditions may subject theelectrical connectors to moisture. With repeated use, mechanicalconnectors are also subject to wear and eventual failure. Third,inductively coupled lamps inherently provide a lower risk of anelectrical hazard at the lamp assembly. As noted above, the lampassembly is electrically separated from the power source. All power mustbe inductively passed from the power source to the lamp assembly.Because there is an intrinsic limit on the amount of power that can beinductively passed to the lamp assembly, the amount of power at the lampassembly is limited and the risk of electrical hazards is reduced.

[0004] Although conventional inductively coupled lamps provide a numberof important advantages over directly connected lamps, they do suffersignificant drawbacks. An inductive coupling is inherently lessefficient than a direct electrical connector. This is partly due to thepower required to create and sustain the electromagnetic field. Theprimary inefficiencies in a conventional inductive coupling result froma poorly tuned circuit. These inefficiencies are manifest in increasedheat gain and in noise created by vibration in the primary andsecondary. The efficiency issues are exaggerated with higher powerlighting applications. In addition, existing lamp circuits requireprecise alignment of the primary and secondary to provide any reasonablelevel of efficiency. This requires more precise tolerances and limitsthe configuration and layout of the lamp assembly and the overall lamp.

[0005] One of the largest reliability issues facing the lamp industry iscaused by the penetration of the lamp sleeve by wires or otherelectrical conductors. Typically, the wires pass into the interior ofthe lamp through a glass stem. Because glass does not readily adhere toand seal around the wires, there is a material risk of lamp leakage atthe point the wires penetrate the lamp. Although efforts have been madeto optimize the seal, this remains a significant reliability concern.

[0006] With conventional inductively powered lamps, there are alsoreliability issues associated with exposure of the lamp circuitcomponents to the environment, for example, water and moisture from theenvironment can damage circuit components. To address this concern, atleast one inductively powered lighting system encloses the entire lampassembly within a sealed enclosure. U.S. Pat. No. 5,264,997 toHutchisson et al discloses a lamp that is mounted to a printed wiringboard that is spaced from the secondary on a plurality of posts. Theprinted wiring board includes various electrical component required foroperation of the inductive coupling. Separate shell and lens componentsare sealed together to form a leaktight enclosure around the lamp, theprinted wiring board and the secondary. The shell is specially shaped toreceive the secondary and to be interfitted with a socket containing theprimary. Although the sealed enclosure provides improved protection fromenvironmental conditions, it is relatively bulky and only provides lighttransmission in the direction of the lens.

[0007] As can be seen, there remains a need for an inductively coupledlamp assembly that is efficient, provides improved reliability in avariety of conditions and is easily adapted to many different lampconfigurations.

SUMMARY OF THE INVENTION

[0008] The aforementioned problems are overcome by the present inventionwherein a lamp assembly is provided with a lamp, an inductive secondaryfor powering the lamp and a capacitor. The capacitor is connected inseries with the lamp and the secondary, and is selected to have areactance at the operating frequency that is approximately equal to orslightly less than the combined impedance of the lamp and the secondaryat operating temperature. As a result, the lamp circuit operates at ornear resonance. With electric-discharge lamps, the series capacitor alsofunctions to limit the flow of current in the secondary circuit,precluding an uncontrolled increase in current that would otherwiseoccur with an electric-discharge lamp.

[0009] In another aspect, the present invention provides an inductivelypowered lamp assembly in which the entire lamp assembly circuit issealed within a transparent sleeve. Preferably, the entire lamp assemblycircuit, including secondary and any associated capacitor, is sealedwithin the sleeve of the lamp. In an alternative embodiment, thesecondary and lamp, as well as any capacitor and starter device, arecontained within a second closed plastic, Teflon, glass or quartz sleevewith no wires or other elements penetrating the sleeve. The void definedbetween the second sleeve and the lamp sleeve is preferably evacuated orfilled with a functional gas to provide the desire level of heatconduction or insulation.

[0010] In a further aspect, the present invention provides a remotelyactuated switch to provide preheat of electric-discharge lamp. Theswitch is provided to short the electrodes across the secondary for aspecific period of time at lamp start-up. In addition this circuit mayhave a series resistor to help limit preheat current. In one embodiment,the switch is an electromagnetic switch that is preferably actuated by amagnetic field generated by a corresponding coil in a lamp controlcircuit.

[0011] The present invention provides a simple and inexpensive lampassembly for use with inductively powered lighting. Because the lampassembly operates at or near resonance, it has a high power factor andis highly efficient. This reduces power loss through heat build up andalso provides for quiet operation of the inductive coupling—even inrelatively high power applications. The efficiency of the secondarycircuit demands less precise alignment between the primary andsecondary, thereby permitting a greater degree of latitude in the layoutand configuration of the lamp and the lamp assembly. The sealed sleeveprovides the lamp circuit with improved protection from the environmentwithout limiting the transmission of light from the lamp. Although withsome light sources, the spectrums emitted may see losses based on thespecific transmissive properties of the materials used in the sleeves,for example, some materials are not highly transmissive to UV light. Thepresent invention allows functional gases to be entrapped within thesealed sleeve to increase or reduce the degree to which the lamp isisolated from the environment. Further, by enclosing the entire lampcircuit within the lamp sleeve, the need for wires or electrical leadsthat penetrate the sleeve can be eliminated. This greatly improves thereliability of the lamp while dramatically reducing manufacturinglosses. Also, the electromagnetic switch of the present inventionprovides an inexpensive and reliable alternative to conventional startercircuits.

[0012] These and other objects, advantages, and features of theinvention will be readily understood and appreciated by reference to thedetailed description of the invention and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a sectional view of a lamp assembly according to oneembodiment of the present invention;

[0014]FIG. 2 is a sectional view the lamp assembly of FIG. 1 takenperpendicularly to the sectional view of FIG. 1;

[0015]FIG. 3 is a schematic diagram of a lamp circuit according to oneembodiment of the present invention;

[0016]FIG. 4 is a sectional view of an alternative lamp assembly havingan incandescent lamp;

[0017]FIG. 5 is a sectional view of an alternative lamp assembly havingan incandescent lamp with a universal base;

[0018]FIG. 6 is a sectional view of an alternative lamp assembly havinga halogen lamp;

[0019]FIG. 7 is a sectional view of an alternative lamp assembly havinga halogen lamp with the base located outside of the lamp sleeve;

[0020]FIG. 8 is a sectional view of an alternative lamp assembly havinga halogen lamp with no base;

[0021]FIG. 9 is a sectional view of an alternative lamp assembly havinga fluorescent lamp with no outer sleeve;

[0022]FIG. 10 is a sectional view of an alternative lamp assembly havinga type T-5 or T-8 fluorescent lamp;

[0023]FIG. 11 is a schematic diagram of a lamp circuit for the lampassembly of FIG. 10;

[0024]FIG. 12 is a schematic diagram of an alternative lamp circuit forthe lamp assembly of FIG. 10;

[0025]FIG. 13 is a schematic diagram of yet another alternative lampcircuit for the lamp assembly of FIG. 10;

[0026]FIG. 14 is a schematic diagram of a further alternative lampcircuit for the lamp assembly of FIG. 10;

[0027]FIG. 15 is a sectional view of an alternative lamp assembly havinga PL type fluorescent lamp;

[0028]FIG. 16 is a sectional view of the alternative lamp assemblyhaving a PL type fluorescent lamp taken perpendicularly to the sectionalview of FIG. 15;

[0029]FIG. 17 is a partially sectional exploded view of an alternativelamp assembly;

[0030]FIG. 18 is a sectional view of a portion of the alternative lampassembly of FIG. 16;

[0031]FIG. 19 is a sectional view of a portion of an alternative lampassembly; and

[0032]FIG. 20 is a sectional view of a portion of yet anotheralternative lamp assembly.

DETAILED DESCRIPTION OF INVENTION

[0033] A lamp assembly according to an embodiment of the presentinvention is shown in FIGS. 1 and 2, and is generally designated 10. Forpurposes of disclosure, the present invention is first described inconnection with a conventional type PL-S 11 watt UV lamp converted foruse at 38 watt, such as the type used in a water treatment device. Thelamp assembly 10 generally includes a lamp circuit 12 and an outersleeve 70. The lamp circuit 12 includes a secondary 14, a capacitor 16and a lamp 18, all connected in series (See FIG. 3). The secondary 14inductively receives power from the primary (not shown) of an associatedballast (not shown). The series capacitor 16 is specially tuned, asdescribed in more detail below, so that the lamp circuit operates atresonance under specific operating conditions. The entire lamp circuit12 is fully enclosed within the outer sleeve 70, including the secondary14, capacitor 16 and lamp 18. At least a portion of the outer sleeve 70is transparent and is not penetrated by electrical wires or otherelements.

[0034] Although the following embodiment is described in connection witha type PL-S 38 watt UV lamp, the present invention is intended and wellsuited for use with lamps of various types and styles, includingelectric-discharge, incandescent, pulsed white light and light emittingdiode (“LED”) lamps. This disclosure presents various alternativeembodiments showing incandescent lamps and electric-discharge lamps.These examples are provided to illustrate the broad applicability andadaptability of the present invention, and not to provide any limit onthe scope of the claims.

[0035] A wide variety of ballasts capable of powering the inductive lampassembly of the present invention are well known to those skilled in thefield. Accordingly, the ballast will not be described in detail. Oneballast particularly well-suited for use with the type PL-S 38W UV lampof the illustrated embodiment is disclosed in U.S. application Ser. No.90/592,194 entitled “Fluid Treatment System,” which was filed on Jun.12, 2000, which is incorporated herein by reference in its entirety.This ballast can be readily adapted to provide efficient operation ofall of the disclosed embodiments of the present invention.

[0036] I. Lamp Configuration

[0037] As noted above, the type PL-S 38W UV lamp preferably includes anouter sleeve 70 that encloses the lamp circuit 12 to protect it from theenvironment (See FIGS. 1 and 2). The outer sleeve 70 preferably includesa main body 90 and a cap 92. The main body 90 is a generally cylindricaltube having an open end and a closed end. After the lamp circuit 12 isinstalled within the main body 90, the cap 92 is sealed over the openend of the main body 90 to fully enclose the lamp circuit 12. The lampcircuit 12 generally includes a secondary 14, a capacitor 16 and a lamp18. As described below, the lamp circuit 12 may also include a starter35 (See FIG. 2). The lamp 18 is a generally conventional PL-S type lamphaving a quartz sleeve with two parallel legs 72 a-b that areinterconnected to cooperatively define a chamber 28. The chamber 28 ispartially evacuated and contains the desired electric-discharge gas,such as mercury vapor. A stem 32 a-b is located at the base of each leg72 a-b. A pair of conventional or custom designed electrodes 26 a-b aredisposed within the chamber 28, one mounted atop each of the stems 32a-b. In this embodiment, the outer sleeve 70 is preferably manufacturedfrom quartz to permit the efficient passage of UV light. In non-UVapplications, the outer sleeve may be manufactured from glass, Teflon orplastic, depending in part on the heat generated by the lamp and theoperating environment of the lamp. For example, an alternative outersleeve can be manufactured from a length of Teflon tubing having sealedopposite ends (not shown). The Teflon tubing can be fitted over theremainder of the lamp assembly, and its opposite ends can be crimped orotherwise sealed to close the Teflon sleeve. Preferably, each end of theTeflon tubing is folded back onto itself and crimped using heat andpressure.

[0038] The lamp assembly 10 also includes a base 50 and a support 86that hold opposite ends the lamp 18 within the outer sleeve 70. The base50 is generally cylindrical and dimensioned to be fitted closely withinthe outer sleeve 70. In addition to holding one end of the lamp 18, thebase 50 also receives the various electrical components of the lampcircuit 12. The base 50 defines an annular recess 80 to receive thewindings of the secondary 14, a pair of apertures 82 a-b to receive thebase end of each leg 72 a-b, and a pair of voids 84 a-b to contain thecapacitor 16 and any desired starter 35. The lamp assembly 10 may alsoinclude a heat reflector 58 disposed between the secondary and theelectrodes 36 a-b. The heat reflector 58 is preferably shaped to matchthe cross-sectional shape of the lamp sleeve 52 at the point where it ismounted, and is preferably manufactured from a conventional reflectivematerial, such as aluminum or aluminum foil on a suitable substrate. Thesupport 86 is generally disc-shaped and is dimensioned to be fittedclosely within the outer sleeve 70. The support 86 preferably includes atab 88 to be frictionally fitted between the legs 72 a-b of the quartzsleeve 52. The precise design and configuration of the base 50 andsupport 86 can vary among applications depending on the design andconfiguration of the outer sleeve 70 and the various components of thelamp circuit 12. The base 50 and support 86 are preferably manufacturedfrom materials capable of withstanding high heat, such as ceramic orhigh temperature plastics.

[0039] In one embodiment, the void 96 defined between the outer sleeve70 and the lamp sleeve 52 is configured to provide the lamp assemblywith the desired conductive or insulative properties. For example, thisvoid 96 can be evacuated to insulate the lamp from cold environments.Alternatively, the void 96 can be filled with heavier gases, such asargon and neon, or fluids to conduct heat in hot environments. Theconduction of heat from lamps in hot environments will help to protectthe lamp from overheating and may also help to provide maximumintensity.

[0040] In some applications, the lamp assembly 10 may also include amechanism that permits the ballast to sense the presence of the lampassembly 10. This permits the ballast to power the primary (not shown)only when the lamp assembly 10 is installed. Although the sensingmechanism is not necessary in many applications, particularly inlow-power applications, it does provide a more efficient design thatconserves power, reduces heat build-up and protects the primary fromcertain types of damage associated with continuous operation. In oneembodiment, the lamp assembly 10 includes a sensing magnet 60 and theballast (not shown), or an associated control circuit, includes a reedswitch (not shown) that is activated by the sensing magnet 60. Morespecifically, when the lamp assembly 10 is installed, the sensing magnet60 is positioned adjacent to reed switch (not shown). The magnetic fieldfrom the sensing magnet 60 causes the reed switch 62 to close, therebyproviding a signal to the ballast or control circuit that the lampassembly 10 is in place. The sensing magnet is preferably mounted to thebase 50, but may be mounted in other locations as desired.Alternatively, the sensing magnet 60 and reed switch (not shown) can bereplaced by a mechanical switch (not shown). For example, a switch canbe disposed where it is mechanically closed by installation of the lampassembly 10. Another alternative is to provide the lamp with a manuallyactuated on/off switch, for example, a toggle switch, that selectivelyturns the ballast on and off.

[0041] II. Lamp Circuit

[0042] The lamp circuit 12 will now be described in connection with thetype PL-S 38W UV lamp described above (See FIGS. 1 and 2). As notedabove, the lamp circuit 12 generally includes a lamp 18, a secondary 14and a capacitor 16. A schematic diagram of a lamp circuit 12 is shown inFIG. 3. In this embodiment, the lamp circuit 12 includes a singlesecondary 14, preferably in the form of a coil of small diameter wire22. The precise characteristics of the secondary 14 will vary fromapplication to application as a function of the primary (not shown) andthe load (e.g. the lamp). The wire 22 is preferably conventional magnetor LITZ wire depending on the power settings and heat dissipation. Thewire is preferably wrapped around the base 50 within the annular recess80, which provides the secondary 14 with a hollow core. If desired, thehollow core 24 can be replaced by other conventional cores. The type ofwire, the number of turns of wire and the diameter of the core (andconsequently the diameter of the turns of wire) will vary fromapplication to application, depending on various factors such as thecharacteristics of the primary and the load of the lamp 18. Theinductance of the secondary 14 is selected as a function of theoperating frequency and the impedance of the load (i.e. the lamp) at thesupplied power. More specifically, the inductance of the secondary 14 isdetermined by the following formula:${{Inductance}\quad {of}\quad {the}\quad {Secondary}} = \frac{{Impedance}\quad {of}\quad {the}\quad {Load}}{2 \times {Operating}\quad {Frequency}}$

[0043] In the described 38 watt embodiment, the secondary 14 isconfigured to receive power from a primary operating at approximately100 kilohertz. The secondary 14 includes 72 turns of wire and theprimary includes 135 turns of wire. In the described 38 watt embodiment,the secondary 14 has a value of 196 microhenries at 100 kilohertz,having a reactance of approximately 123 ohms. The secondary 14 ispreferably located within the base 50 of the lamp assembly 10. Thediameter of the secondary 14 is preferably selected to closely fit withthe base 50. The secondary 14 is electrically connected to lamp 18 byleads 51 a-b. Although the secondary 14 is preferably circular, it mayvary in shape from application to application. For example, thesecondary may be square, oval, triangular, trapezoidal, hexagonal oreven spherical. The secondary is preferably positioned internally orexternally concentric to the primary, or the two coils may be placed endto end.

[0044] The capacitor 16 is selected to provide optimum power factorcorrection given the mechanical constraints, thereby providing resonancein the lamp circuit 12. The power factor is preferably 0.90 or better,and more preferably 0.96 or better, but in some applications lowervalues may be acceptable. Without sufficient power factor correction,the reactive currents in the secondary will reflect back into theprimary as a lower impedance load. This would cause a shift upward inoperating power and current, as well as higher losses in the form ofheat gain in the primary circuit. This effect is contrary to what onemight initially expect but is in fact due to the inverse nature ofreflected impedance within a series resonant primary circuit. Experiencehas revealed that reactive currents and losses in the primary increasevery quickly at factors below 0.90. This can have a material adverseimpact on efficiency, especially when it is considered that these lossesare additive to the losses caused by coupling coefficient and dcresistances. In general, the capacitor 16 is selected to have areactance that is approximately equal to or slightly less than theresistive impedance of the lamp 18 and the reactive impedance of thesecondary 14 when the lamp 18 is at its operating temperature. Like theinductance of the secondary 14, the reactance of the capacitor isselected as a function of the operating frequency and the impedance ofthe load (i.e. the lamp) at the supplied power. More specifically, thereactance of the capacitor is selected in accordance with the followingformula:${{Reactance}\quad {of}\quad {the}\quad {Capacitor}} = \frac{1}{{Impendance}\quad {of}\quad {the}\quad {Load} \times 2 \times {Operating}\quad {Frequency}}$

[0045] At this reactance, the capacitor 16, secondary 14 and lamp 18will be operating close to resonance, providing a high power factor andconsequently high efficiency. In the illustrated embodiment, thecapacitor 16 has a value of approximately 12.9 nanofarads (nf). Thisvalue will change in response to variations in the primary (not shown),secondary 14 and/or lamp 18.

[0046] The secondary and capacitor formulas presented above provide arough approximation of the desired capacitor and secondary reactancevalues. To provide more refined values (and thereby fine-tune the powerfactor, current limiting effect, and overall operating parameters), aniterative testing procedure may be employed. This iterative testing maybe required in some applications to provide the desire level ofefficiency in the secondary circuit. The operating parameters of thesedesigns include preheat, strike voltage, and operating current. All ofthese parameters can be configured through this tuning process alongwith changes in values of ratios, capacitance and inductance.

[0047] Although the capacitor 16 is preferably tuned to the secondary 14and lamp 18 when the lamp 18 is at operating temperature, the capacitor16 can alternatively be tuned to provide optimum efficiency at othertimes. For example, in electric-discharge lamps where greater current isrequired to start the lamp, the present invention can be employed toboost the circuit during start-up. In such applications, the capacitoris selected to have a reactance that is approximately equal to thecombined impedance of the secondary and the lamp at start-up temperature(rather than at operating temperature). This will increase theefficiency of the lamp circuit during start-up, permitting the use of aballast with a lower current maximum.

[0048] Given the nature of plasma, electric-discharge lamps attempt tomaintain voltage at a substantially constant inherent voltage. As aresult, if the secondary 14 generates voltage in excess of the inherentvoltage of the lamp, the lamp will attempt to consume the excess power.Because the resistance of in an electric-discharge lamp decreases inresponse to the flow of current, the lamp has the potential to drawingincreasingly more current until the circuit limits or self-destructs.This concern is addressed by the capacitor 16, which functions to limitthe current supplied to the lamp. The current limiting function is aninherent characteristic of a capacitor. It has been determined that thecapacitor value required to place the secondary circuit at resonance isapproximately equal to the capacitor value needed to provide appropriatecurrent limiting. Accordingly, it has been determined that the currentlimiting function is achieved in the present invention by selecting acapacitor value appropriate to provide unity power factor.

[0049] When the present invention is incorporated into anelectric-discharge lamp assembly, the lamp circuit 12 preferablyincludes a conventional starter 35 (See FIG. 2), glow bulb or otherequivalent mechanism. Starters and glow bulbs are well known and willtherefore not be described in detail in this application. In oneembodiment of an electric-discharge lamp assembly, the conventionalstarter is replaced by a remotely actuatable switch, such aselectromagnetic switch 34 (See FIG. 3). The electromagnetic switch 34 iswired in series between the electrodes 36 a-b, thereby selectivelypermitting the switch 34 to close the circuit between the electrodes 36a-b. When closed, the switch 34 permits current to flow directly throughthe electrodes 36 a-b, rather than through requiring it to arc throughthe gas. As a result, when the switch 34 is closed, the electrodes 36a-b are rapidly heated. The electromagnetic switch 34 is preferablyarranged substantially perpendicular to the field of the primary so thatthe electromagnetic switch 34 is not actuated by the electromagneticfield of the primary. Instead, a separate coil 38 is positioned adjacentto the electromagnetic switch 34 where it can be charged to selectivelyclose the switch 34. A microprocessor 40 preferably controls operationof the coil 38 and therefore the electromagnetic switch 34. Themicroprocessor 40 is programmed to charge the coil 38 for a fixed periodof time each time that the lamp circuit is powered on. This closes theelectromagnetic switch 34 shorting the electrodes 36 a-b together.Alternatively, the microprocessor 40 can be replaced by a conventionalone-shot timer circuit (not shown) that is configured to charge the coilfor the desired period of time each time that the lamp is started.

[0050] III. Alternative Embodiments

[0051] The configuration of the lamp assembly may vary materially fromapplication to application depending largely on the type of lamp and theassociated power requirements. The present invention can be readilymodified to permit use with a wide variety of existing lighting systems.The following alternative embodiments describe a variety of alternativeembodiments adapted for various uses. These alternative embodiments areintended to be illustrative of the wide adaptability of the presentinvention, and not intended to be exhaustive.

[0052] An alternative embodiment showing the present inventionincorporated into an incandescent lamp is shown in FIG. 4. In thisembodiment, the lamp assembly 110 includes a glass sleeve 152 and aplastic base 150. The glass sleeve 152 is generally bulb shaped andincludes an inwardly turned and generally cylindrical stem 132. Asecondary 114 is mounted within the glass sleeve 152 about stem 132. Afilament 136 is mounted to the secondary 114 extending upwardly into thebulbous portion of the glass sleeve 152 in a conventional manner. Unlikethe embodiment described above, the base 150 in this embodiment isfitted to the outside of the glass sleeve 152. The base 150 isconfigured to be interfitted with a corresponding socket (not shown).The illustrated base 150 is generally circular and includes an annularrecess 156 configured to snap fit into a corresponding socket (notshown). The base 150 also includes an upper flange 158 that provides agripping edge for removing the lamp assembly 110 from a socket (notshown). The base 150 may, however, take on a variety of differentconfigurations to permit the lamp assembly 110 to mechanical connect toa variety of different sockets. For example, the base may be externallythreaded. As illustrated, lamp assembly 110 also preferably includes asensing magnet 160. The sensing magnet 160 may be fitted into acorresponding retaining wall 162 in the bottom of base 150. As describedabove, the sensing magnet 160 functions with a magnetically actuatedswitch, such as a reed switch, to advise the primary or control circuitof the presence of the lamp assembly 110. This permits the primary to bepowered only when a lamp assembly 110 is in place. As shown in FIG. 5,the incandescent lamp assembly 110′ can be configured to operate with aconventional universal base. In this embodiment, the base 150′ includesa pair of mounting pins 156 a-b that are configured to interlock withmatching slots in a conventional universal base lamp socket (not shown).

[0053] An alternative embodiment showing the present inventionincorporated into a halogen lamp is shown in FIG. 6. In this embodiment,the lamp assembly 210 generally includes a quartz sleeve 252 and aceramic base 250. The materials of the sleeve 252 and base 250 areselected to withstand the particularly high temperature at which halogenlamps operate. The quartz sleeve 252 is preferably fully sealed and doesnot include any penetrating elements, such as wires or other electricalconnectors. A filament 236, secondary 214 and capacitor 216 are enclosedwithin the quartz sleeve 252. In some applications, the capacitor 216may not be necessary to provide an acceptable level of efficiency andmay accordingly be eliminated. The lamp assembly 210 further includes aheat reflector 258 disposed between the filament 236 and the secondary214. The base 250 may include quarter turn threads 256 a-b that arethreadedly interfitted within a corresponding socket (not shown). Thebase 250 can be provided with alternative structure to facilitateinstallation in the socket. A sensing magnet 260 is preferably mountedto the inside bottom surface of the base 250.

[0054] In an alternative halogen lamp assembly 210′, the quartz sleeve252′ is shortened to terminate just within the neck of the base 250′(See FIG. 7). The secondary 214′ is moved outside of the quartz sleeve252′ and is positioned in the base 250′. In this embodiment, thesecondary 214′ is isolated from the heat of the filament 236′. Thisembodiment may also include a sensing magnet 260′.

[0055] In another alternative halogen lamp assembly 210″, the base iseliminated and the sensing magnet 260″ is moved into the interior of thesealed quartz sleeve 252″. As shown in FIG. 8, the quartz sleeve 252″defines an annular recess 256″ that extends entirely around the sleeve252″ to permit the lamp assembly 210″ to be snap-fitted into acorresponding socket (not shown).

[0056] Another alternative embodiment is shown in FIG. 9. In thisembodiment, the lamp assembly 310 includes a base 350 that is disposedoutside of the lamp sleeve 352 and the lamp assembly 310 does notinclude an outer sleeve. The lamp sleeve 352 encloses the electrodes 336a-b and the desired electric-discharge gas, for example, mercury vapor.The secondary 314, capacitor 316, any desired starter mechanism (such asa conventional starter or the magnetically actuated switch describedabove) and all electrical connections are contained inside the base 350,but outside of the lamp sleeve 352. The base 350 is configured tocorrespond with a conventional universal base, and includes a pair ofmounting pins 356 a-b that interlock with matching slots in the lampsocket (not shown). The base 350 may alternatively be configured tomatch with other socket configurations. A sensing magnet 360 ispreferably mounted in the base 350. If desired, an outer sleeve (notshown) can be added to this lamp assembly 310 to enhance its protectionfrom the environment. If included, the outer sleeve would preferablyextend around the entire lamp assembly, except for the base 350. Thebase 350 would be mounted to the exterior of the outer sleeve where itcan be interfitted with a lamp socket.

[0057] An alternative embodiment showing the present inventionincorporated into a type T5 or T8 fluorescent lamp is shown in FIGS. 10and 11. The lamp assembly 410 includes an elongated glass sleeve 452 anda pair of secondaries 414 a-b—one located at each end of the sleeve 452.Given the different physical location of the two secondaries 414 a-b,the power supply is preferably configured to include two separateprimaries (not shown) that separately power the two secondaries 414 a-b.The two primaries are disposed adjacent to the corresponding secondary414 a-b. It is typical to evenly distribute the power between the coils414 a-b, but is not strictly necessary. Preferably, the secondary coils414 a-b are set to opposite polarity with each primary and secondarycombination being configured to sustain half of the voltage and currentneeded to power the lamp. The sleeve 452 preferably includes an annularstem 432 a-b formed at each opposite end to receive the secondaries 414a-b. An electrode 436 a-b is electrically connected to each secondary414 a-b. A capacitor 416 is connected in series between the twosecondaries 414 a-b. The preferred method for calculating the value ofthe capacitors 416 a-b in this embodiment is to initially analyze thecircuit as though only a single coil was going to be used in accordancewith the methodology described above (in connection with the firstdisclosed embodiment). The value of the single capacitor of thishypothetical configuration is then halved to provide the value for eachof the two capacitors 416 a-b of this embodiment. Optional end caps 420a-b, preferably of aluminum, are fitted over opposite ends of the sleeve452. The lamp assembly 410 may include a conventional starter 435 asshown in FIG. 11. In this embodiment, conductors 498 a-b are required toextend between the two secondary coils 414 a-b. The conductors 498 a-bare preferably contained within the lamp sleeve 452. As an alternative,magnetic switches 434 a-b, or other remotely actuated switches, are usedin place of a conventional starter. As shown in FIG. 12, the lampassembly 410′ includes a separate switch 434 a-b that is mounted inseries between each secondary coil 414 a-b′and it's correspondingfilament or electrode 436 a-b′. By closing the switches 434 a-b, thepower from each secondary coil 414 a-b′ is supplied directly to itscorresponding filament. In this embodiment, only a single conductor 498′is required to extend between the secondary coils 414 a-b′. Thecapacitor 416′ is connected in series along the conductor 498′.

[0058] An alternative circuit for a dual-coil lamp assembly 410″ isshown in FIG. 13. In this circuit, no conductors are required to extendbetween the two secondary coils 414 a-b″. Instead, each secondary coil414 a-b″ includes a dedicated switch 434 a-b″ and a dedicated capacitor416 a-b″. The lamp controller is preferably configured to open and closethe two switches 434 a-b″ in unison. The preferred method forcalculating the value of the capacitors 416 a-b″ is to initially analyzethe circuit in accordance with the first disclosed embodiment as thoughonly a single coil and single capacitor were going to be used. The valueof the single capacitor of this hypothetical configuration is thenhalved to provide the value for each of the two capacitors 416 a-b″ ofthis embodiment. In some applications, the power may not be evenlydistributed between the two secondaries. In such applications, the ratiobetween the value of the two capacitors should be equivalent to theratio of the power between the two secondaries.

[0059] Another alternative circuit for a dual-coil lamp 410″' is shownin FIG. 14. In this alternative, only a single secondary coil 414″' isprovided. The secondary coil 414″' is connected to electrodes 436 a-b″'located at opposite ends of the lamp. This circuit includes a pair ofconductors 498 a-b″' that extend between the coils. A conventionalstarter 435″' or other starter mechanism, such as magnetic switches, isincluded to start the lamp. In this embodiment, the value of thecapacitor 416″' is preferably selected in accordance with the method ofthe first disclosed embodiment.

[0060] A further alternative embodiment showing the present inventionadapted for use in a PL type fluorescent lamp is shown in FIGS. 15 and16. In this embodiment, the entire lamp circuit is enclosed within thelamp sleeve 552, and no outer sleeve is included. As illustrated, thelamp assembly 510 includes a glass sleeve 552 having two interconnectedlegs 502 a-b. This lamp assembly 510 may include any of the dual-coillamp circuits described above. For purposes of disclosure, thisembodiment is described in connection with a lamp assembly 510 having aseparate secondary 514 a-b mounted in the base of each leg 502 a-b. Thetwo secondaries 514 a-b are preferably powered by a single primary (notshown) surrounding or adjacent to one end of the lamp assembly 510. Eachsecondary 514 a-b is connected in series with an electrode 536 a-b, acapacitor 516 a-b and a magnetically actuated starter switch 534 a-b.The value of each capacitor 516 a-b is selected as described above isconnection with the embodiment of FIG. 13. This lamp assembly 510 mayalso include a sensing magnet 560.

[0061] An alternative lamp assembly 610 having an alternative sealingstructure is shown in FIGS. 17 and 18. As shown in the exploded view ofFIG. 17, the lamp assembly 610 generally includes a locking ring 602, anouter sleeve 670, a lamp 618 and a base 650. The locking ring 602, outersleeve 670 and base 650 cooperate to seal the lamp assembly 610. Asperhaps best shown in FIG. 18, the base 650 includes a cylindricalcentral portion 652 that is shaped to receive the secondary 614 and thelamp 618. More specifically, the lamp 618 is mounted to a printedcircuit board assembly (“PCBA”) 654, which will preferably also supportany capacitor or starter mechanism incorporated into the lamp assembly610. The lamp/PCBA combination is mounted to the base 650, for example,by fasteners or a snap-fit. The base 650 also includes annular channel656 that extends around the base 650 to receive the end of the outersleeve 670. An o-ring 604 is fitted around the central portion 652within the annular channel 656. The base 650 may include an annular rib(not shown) to prevent the o-ring 604 from riding up the central portion652. Once assembled, the o-ring 604 is disposed between the innerdiameter of the outer sleeve 670 and the outer diameter of the centralportion 652 of the base 650. In this position, the o-ring 604 not onlyprovides an effective seal against water, but it also functions as avibration damper that cushions vibrations between the lamp and the outersleeve 670. The outer sleeve 670 is a generally cylindrical tube havinga closed end and an open end. A bead 672 or other flange extends aroundthe open end of the outer sleeve 670. The outer sleeve 670 is secured tothe base 650 by the locking ring 602. The locking ring 602 is generallyring-shaped and is fitted over the outer sleeve 670 and the base 650.The locking ring 602 has a generally inverted L-shaped cross sectionwith a radial leg 674 and an axial leg 676. The radial leg 674 engagesthe bead 672 and the axial leg 676 engages the outer surface of the base650. Alternatively, as shown in FIG. 19, the locking ring 602′ and base650′ can be configured so that the axial leg 676′ is fitted within theannular channel 656′. In either case, the axial leg 676 or 676′ issecured to the base 650 or 650′ to lock the outer sleeve 670 in theannular channel 656 of the base 650. The locking ring 602 may beattached to the base 650 using various attachment methods. For example,the locking ring 602 may be sonic or heat welded to the base 650.Alternatively, the lamp assembly 610″ may include a locking ring 602″having a lower flange 678 (See FIG. 20) that permits the locking ring602′ to be snap-fitted onto the base 650′, or the locking ring and basecan includes threads (not shown) to permit the locking ring to bethreaded to the base.

[0062] The above description is that of various embodiments of theinvention. Various alterations and changes can be made without departingfrom the spirit and broader aspects of the invention as defined in theappended claims, which are to be interpreted in accordance with theprinciples of patent law including the doctrine of equivalents. Anyreference to claim elements in the singular, for example, using thearticles

a,

an,

the

or

said,

is not to be construed as limiting the element to the singular.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows: 1- An inductively poweredlamp assembly comprising: an inductive secondary to receive power froman inductive primary, said inductive primary having a reactance; a lampdisposed in series with said secondary, said lamp having an impedance;and a capacitor disposed in series with said inductive secondary andsaid lamp, said capacitor selected to have a reactance that issubstantially equal to or slightly less than said impedance of said lampand said reactance of said secondary, whereby said capacitor, said lampand said secondary operate substantially at resonance. 2- The lampassembly of claim 1 wherein said reactance of said secondary is furtherdefined as an operating reactance; said impedance of said lamp isfurther defined as an operating impedance; wherein said capacitor, saidlamp and said secondary operate substantially in resonance when saidlamp and said secondary are substantially at operating temperature. 3-The lamp assembly of claim 2 wherein said secondary is further definedas a coil of LITZ wire. 4- The lamp assembly of claim 2 wherein saidsecondary is further defined as a coil of magnet wire. 5- The lampassembly of claim 3 wherein said lamp assembly includes a closed sleevesurrounding and fully enclosing said secondary, said lamp and saidcapacitor, said sleeve being unpenetrated. 6- The lamp assembly of claim5 wherein said closed sleeve is substantially transparent to light of adesired wave length. 7- The lamp assembly of claim 3 wherein said lampincludes a lamp sleeve, said capacitor and said secondary being fullyenclosed within said lamp sleeve, whereby said lamp sleeve isunpenetrated. 8- The lamp assembly of claim 7 wherein said lamp sleeveis substantially transparent to light of a desire wave length. 9- Thelamp assembly of claim 8 wherein said lamp is further defined as anincandescent lamp. 10- The lamp assembly of claim 8 wherein said lamp isfurther defined as an electric discharge lamp. 11- The lamp assembly ofclaim 8 wherein said lamp is further defined as a light emitting diode.12- The lamp assembly of claim 3 wherein said secondary is coaxial withsaid lamp. 13- An inductively powered lamp assembly comprising: aninductive secondary to receive power from an inductive primary, saidinductive secondary having a reactance; a lamp disposed in series withsaid secondary, said lamp having an impedance that is substantiallyequal to said reactance of said secondary; and a capacitor disposed inseries with said secondary and said lamp, said capacitor having areactance that is substantially equal to or slightly less than saidimpedance of said lamp and said reactance of said secondary. 14- Thelamp assembly of claim 13 wherein said reactance of said secondary isfurther defined as an operating reactance; said impedance of said lampis further defined as an operating impedance; wherein said lamp and saidsecondary operate substantially in resonance when said lamp and saidsecondary are substantially at operating temperature. 15- The lampassembly of claim 14 wherein said secondary is further defined as a coilof LITZ wire. 16- The lamp assembly of claim 15 wherein said secondaryis further defined as a coil of magnet wire. 17- The lamp assembly ofclaim 15 wherein said lamp assembly includes a closed transparent sleevesurrounding and fully enclosing said secondary, said capacitor and saidlamp, said sleeve being unpenetrated. 18- The lamp assembly of claim 17wherein said lamp includes a lamp sleeve, said lamp sleeve beingsubstantially transparent to light of a desired wave length, saidsecondary being fully enclosed within said lamp sleeve, whereby saidlamp sleeve is unpenetrated. 19- The lamp assembly of claim 18 whereinsaid lamp is further defined as an incandescent lamp. 20- The lampassembly of claim 18 wherein said lamp is further defined as an electricdischarge lamp. 21- The lamp assembly of claim 15 wherein said secondaryis coaxial with said lamp. 22- An inductively powered lamp assemblycomprising: a lamp circuit including: an inductive secondary to receivepower from an inductive primary; and a lamp disposed in series with saidsecondary; a transparent sleeve entirely enclosing said lamp circuit.23- The lamp assembly of claim 22, wherein said sleeve defines a chambersurrounding said lamp circuit, said chamber being partially evacuated toinsulate said lamp from the environment. 24- The lamp assembly of claim22, wherein said sleeve defines a chamber surrounding said lamp circuit;and further including a gas filling said chamber, said gas selected toprovide a desired level of heat conduction between said lamp and theenvironment. 25- The lamp assembly of claim 24 wherein said lamp circuitfurther includes a capacitor in series with said lamp and saidsecondary, said capacitor being entirely contained within said sleeve.26- An inductively powered lamp assembly comprising: anelectric-discharge lamp having a pair of electrodes; a secondary toreceive power from an inductive primary, each of said electrodesincluding a first lead electrically connected to said secondary; and amagnetic starter switch operable between open and closed positions inresponse to a magnetic field, each of said electrodes including a secondlead electrically connected to said magnetic starter switch, saidmagnetic starter switch shorting said electrodes across said secondarywhen in said closed position to preheat said lamp. 27- The lamp assemblyof claim 26 wherein said magnetic starter switch is operable in responseto a magnetic field oriented substantially perpendicularly to a magneticfield powering said secondary. 28- An inductively poweredelectric-discharge lamp assembly comprising: a lamp having a pair ofelectrodes and an electric-discharge gas contained within a lamp sleeve;an inductive secondary to receive power from an inductive primary; meansfor electrically connecting said secondary to at least one of saidelectrodes, whereby said secondary provides power to said electrode whensubjected to an appropriate electromagnetic field generated by aninductive primary; and wherein said secondary and said electricallyconnecting means are enclosed within said sleeve, whereby said lamp isself-contained with said sleeve being fully sealed and unpenetrated. 29-The electric discharge lamp assembly of claim 28, wherein said inductivesecondary has a reactance, said lamp having an impedance that issubstantially equal to said reactance of said secondary, said capacitorhaving a reactance that is substantially equal to or slightly less thansaid impedance of said lamp and said reactance of said secondary. 30-The electric discharge lamp assembly of claim 29 further comprising amagnetic starter switch being operable between open and closed positionsin response to a magnetic field, said magnetic starter switch shortingsaid electrodes across said secondary when in said closed position topreheat said lamp. 31- An inductively powered incandescent lamp assemblycomprising: an incandescent lamp having a filament contained within alamp sleeve; an inductive secondary to receive power from an inductiveprimary; means for electrically connecting said secondary to saidfilament, whereby said secondary provides power to said filament whensubjected to an appropriate magnetic field by an inductive primary; andwherein said secondary and said electrically connecting means areenclosed within said sleeve, whereby said lamp is self-contained withsaid sleeve being fully sealed and unpenetrated. 32- The electricdischarge lamp assembly of claim 31 further comprising a capacitorconnected in series with said inductive secondary and said lamp; andwherein said inductive secondary has a reactance, said lamp having animpedance that is substantially equal to said reactance of saidsecondary, said capacitor having a reactance that is substantially equalto or slightly less than said impedance of said lamp and said reactanceof said secondary. 33- An inductively powered electric-discharge lampassembly comprising: first and second secondaries; a lamp having firstand second electrodes, said first electrode being electrically connectedto said first secondary, said second electrode being electricallyconnected to said second secondary; a capacitor connected in seriesbetween said first secondary and said second secondary; and a startermeans for preheating said electrodes, said starter means electricallyconnected in series between said first electrode and said secondelectrode. 34- The electric-discharge lamp assembly of claim 33 wherein:each of said first secondary and said second secondary includes firstand second leads; each of said first electrode and said second electrodeincludes first and second leads, said first lead of said first electrodebeing electrically connected to said first lead of said first secondary,said first lead of said second electrode being electrically connected tosaid first lead of said second secondary; said capacitor being connectedin series between said second lead of said first secondary and saidsecond lead of said second secondary; and said starter means beingelectrically connected in series between said second lead of said firstelectrode and said second lead of said second electrode. 35- Theelectric-discharge lamp assembly of claim 34 wherein said secondarieshave a combined reactance, said lamp having an impedance that issubstantially equal to said combined reactance of said secondaries, saidcapacitor having a reactance that is substantially equal to or slightlyless than said impedance of said lamp and said combined reactance ofsaid secondaries. 36- An inductively powered electric-discharge lampassembly comprising: first and second secondaries; a lamp having firstand second electrodes, said first electrode being electrically connectedto said first secondary, said second electrode being electricallyconnected to said second secondary; a capacitor connected in seriesbetween said first electrode and said second electrode; and first andsecond remotely operable switch means for preheating said electrodes,said first switch means electrically connected in series between saidfirst electrode and said first secondary to selectively short said firstelectrode across said first secondary, said second switch meanselectrically connected in series between said second electrode and saidsecond secondary to selectively short said second electrode across saidsecond secondary. 37- The electric-discharge lamp assembly of claim 36wherein: each of said first secondary and said second secondary includesfirst and second leads; each of said first electrode and said secondelectrode includes first and second leads, said first lead of said firstelectrode being electrically connected to said first lead of said firstsecondary, said first lead of said second electrode being electricallyconnected to said first lead of said second secondary; said capacitorbeing connected in series between said second lead of said firstelectrode and said second lead of said second electrode; said firstswitch means being electrically connected in series between said secondlead of said first electrode and said second lead of said firstsecondary; and said second switch means being electrically connected inseries between said second lead of said second electrode and said secondlead of said second secondary. 38- The electric-discharge lamp assemblyof claim 36 wherein said secondaries have a combined reactance, saidlamp having an impedance that is substantially equal to said combinedreactance of said secondaries, said capacitor having a reactance that issubstantially equal to or slightly less than said impedance of said lampand said combined reactance of said secondaries. 39- An inductivelypowered electric-discharge lamp assembly comprising: first and secondsecondaries; a lamp having first and second electrodes, said firstelectrode being electrically connected to said first secondary, saidsecond electrode being electrically connected to said second secondary;a capacitor connected in series between said first electrode and saidsecond electrode; and first and second remotely operable switch meansfor preheating said electrodes, said first switch means electricallyconnected in series between said first electrode and said firstsecondary to selectively short said first electrode across said firstsecondary, said second switch means electrically connected in seriesbetween said second electrode and said second secondary to selectivelyshort said second electrode across said second secondary. 40- Theelectric-discharge lamp assembly of claim 39 wherein: each of said firstsecondary and said second secondary includes first and second leads;each of said first electrode and said second electrode includes firstand second leads, said first lead of said first electrode beingelectrically connected to said first lead of said first secondary, saidfirst lead of said second electrode being electrically connected to saidfirst lead of said second secondary; said capacitor being connected inseries between said second lead of said first electrode and said secondlead of said second electrode; said first switch means beingelectrically connected in series between said second lead of said firstelectrode and said second lead of said first secondary; and said secondswitch means being electrically connected in series between said secondlead of said second electrode and said second lead of said secondsecondary. 41- The electric-discharge lamp assembly of claim 40 whereinsaid secondaries have a combined reactance, said lamp having animpedance that is substantially equal to said combined reactance of saidsecondaries, said capacitor having a reactance that is substantiallyequal to or slightly less than said impedance of said lamp and saidcombined reactance of said secondaries. 42- An inductively poweredelectric-discharge lamp assembly comprising: first and secondsecondaries; a lamp having first and second electrodes, said firstelectrode being electrically connected to said first secondary, saidsecond electrode being electrically connected to said second secondary;first and second capacitors, said first capacitor connected in seriesbetween said first electrode and said first secondary, said secondcapacitor connected in series between said second electrode and saidsecond secondary; and first and second remotely operable switch meansfor preheating said electrodes, said first switch means electricallyconnected in series between said first electrode and said firstsecondary to selectively short said first electrode across said firstsecondary, said second switch means electrically connected in seriesbetween said second electrode and said second secondary to selectivelyshort said second electrode across said second secondary. 43- Theelectric-discharge lamp assembly of claim 42 wherein: each of said firstsecondary and said second secondary includes first and second leads;each of said first electrode and said second electrode includes firstand second leads, said first lead of said first electrode beingelectrically connected to said first lead of said first secondary, saidfirst lead of said second electrode being electrically connected to saidfirst lead of said second secondary; said first capacitor beingconnected in series between said first lead of said first electrode andsaid first lead of said first secondary; said second capacitor beingconnected in series between said first lead of said second electrode andsaid first lead of said second secondary; said first switch means beingelectrically connected in series between said second lead of said firstelectrode and said second lead of said first secondary; and said secondswitch means being electrically connected in series between said secondlead of said second electrode and said second lead of said secondsecondary. 44- The electric-discharge lamp assembly-of claim 43 whereinsaid lamp has an impedance, a combined reactance of said first secondaryand said second secondary being substantially equal to said impedance ofsaid lamp, a combined reactance of said first capacitor and said secondcapacitor being substantially equal to or slightly less than saidimpedance of said lamp and said combined reactance of said firstsecondary and said second secondary. 45- A method of manufacturing alamp assembly comprising the steps of: connecting a lamp to an inductivesecondary, connecting a capacitor in series with the lamp and theinductive secondary; inserting the lamp, the capacitor, and thesecondary into a structure; and sealing the structure so that the lamp,the capacitor and the secondary do not penetrate the structure. 46- Themethod of claim 45 wherein the capacitor is selected to have a reactancethat is substantially equal to or slightly less than the impedance ofthe lamp and the reactance of the secondary, whereby the capacitor, thelamp and the secondary operate substantially at resonance. 47- Themethod of claim 46 wherein said lamp connecting step includes the stepsof: connecting a first end of a filament wire to a first lead of theinductive secondary; connecting a second end of a filament wire to afirst lead of the capacitor; and connecting a second lead of thecapacitor to a second lead of the inductive secondary. 48- The method ofclaim 46 wherein said lamp connecting step includes the steps of:connecting a first lamp electrode to a first lead of the inductivesecondary; connecting a second lamp electrode to a first lead of thecapacitor; and connecting a second lead of the capacitor to a secondelectrode of the inductive secondary. 49- A method of manufacturing alamp assembly comprising the steps of: connecting a lamp to an inductivesecondary, the lamp having an impedance and the secondary having areactance, connecting a capacitor in series with the lamp and theinductive secondary, the capacitor being selected to have a reactancethat is substantially equal to or slightly less than the impedance ofthe lamp and the reactance of the secondary, whereby the capacitor, thelamp and the secondary operate substantially at resonance. 50- Themethod of claim 49 wherein said lamp connecting step includes the stepsof: connecting a first end of a filament wire to a first lead of theinductive secondary; connecting a second end of a filament wire to afirst lead of the capacitor; and connecting a second lead of thecapacitor to a second lead of the inductive secondary. 51- The method ofclaim 49 wherein said lamp connecting step includes the steps of:connecting a first lamp electrode to a first lead of the inductivesecondary; connecting a second lamp electrode to a first lead of thecapacitor; and connecting a second lead of the capacitor to a secondlead of the inductive secondary. 52- The lamp assembly of claim 17wherein said sleeve is a substantially flexible plastic tube, oppositeends of said tube being sealed to provide a fully sealed enclosure. 53-The lamp assembly of claim 52 wherein said opposite ends of said tubeare crimped. 54- The lamp assembly of claim 53 wherein said plastic tubeis further defined as a Teflon tube. 55- A lamp assembly for aninductively powered lamp comprising: a base; a lamp mounted to saidbase; an outer sleeve mounted to said base about said lamp, said outersleeve having a flange; a flexible, resilient seal disposed between saidbase and said outer sleeve; a locking ring fitted over said sleeve andsecured to said base, said locking ring entrapping said flange to retainsaid outer sleeve in place on said base about said lamp. 56- The lampassembly of claim 55 wherein said base defines an annular channel, saidflange seated within said annular channel. 57- The lamp assembly ofclaim 56 wherein said seal is fitted about said base within said annularchannel. 58- The lamp assembly of claim 57 wherein said locking ringincludes a radial portion and an axial portion, said radial portionengaging said flange, said axial portion being affixed to said base. 59-The lamp assembly of claim 55 wherein said base includes a generallycylindrical portion having an outer surface, said outer sleeve having agenerally cylindrical portion having an inner surface, said seal beingdisposed between and directly engaging said outer surface of said baseand said inner surface of said sleeve. 60- The lamp assembly of claim 59wherein said seal is an o-ring seal.